Combustion apparatus



Filed Aug. 21,, 1934 5 Sheets-Sheet 2 INVENTOR ATToRNEYsW III/l Sept.19, 1939. M HUTTO 2,173,115

COMBUSTION, APPARATUS Filed Aug. 21, 1934 5 Sheets-Sheet 3 7 W lliVENTOR o w' md ATTORNEYS i Sept. 19, 1939.

M. C. HUTTO COMBUSTI ON APPARATUS Filed Aug. 21, 1954 5 Sheets-Sheet 4"mm III lllri -IIIIII ELT/ENTOi ATTORNEYS z a Sept. 19, 1939. Q HUTTQ2,173,115

COMBUST I ON APPARATU S Filed Aug. 21, 1934 5 Sheets-Shee t 5 16 zqs- MWC INVENTOR ATTORNEYS? 3 Patented Sept. .19, 1939 UNITED STATES PArENOFFICE COMBUSTION APPARATUS Marsden C. Hutto, Grosse Pointe, Mich.,assignor to Pressure Generators, Inc.

Application August 21, 1934, Serial No. 740,771

10 Claims.

tion can also be used to heat water to tempera-' tures below .theboiling point, and more particularly to such apparatus in which fuel andair or ygen are admitted to a combustion chamber, ignition and expansionof the fuel taking place in this combustion chamber and the productsofcombustion flowing out in a steady, non-pulsating stream, a water jacketbeing provided around the combustion chamber and exhaust pipe in whichthe steam or hot water is developed.

' This application is a continuation in part of my co-pendingapplication now Patent No. 2,075,849,

dated April 6,, 1937.

The objects of the invention are to provide an efiicient combustionapparatus which will continue to operate at full eificiency for a longtime and contains no internal moving parts; in which the combustiontakes place in a continuous, nonpu sating stream; which is positivelylimited in its Operating pressure and hence safe; in which thecombustion is produced under sub-atmospheric conditions and in acombustion chamber of adequate size and adequately insulated to insuregood combustion; in which proper combustion is provided and the dangerof backfire eliminated by feeding the fuel as an excessively richmixture and diluting this in the combustion chamber; in which desiredturbulence is set up in the combustion chamber to insure goodcombustion; in which cirbonization of thespark plug is avoided and thespark plug adequately cooled;

in which complete combustion is insured by .ad-

mitting the fuel to the bottom of the combustion chamber by properlyproportioning its outlet and by directing this outlet downwardly; inwhich the air is preheated and the heat of the exhaust gas absorbed tocontract the exhaust gases and reduce the volume to be handled by theexhausting device; and inwhich the operation can be controlled entirelyautomatically.

In the accompanying drawings:

Fig. 1 is a vertical central section through a combustion apparatusembodying. the preferred form of my invention.

Figs. 2 and 3 are horizontal sections taken on the correspondinglynumbered lines of Fig. 1.

Fig. 4 is a fragmentary view, on an enlarged scale, similar to Fig. 3and showing the fuel head at the bottom of the combustion chamber.

Fig. 5 is an enlarged fragmentary view similar to Fig. 1 and showing, indetail, the fuel inlet head and associated parts.

Fig. 6 is an enlarged fragmentary vertical sectiontaken on line 6-6,Fig. 3.

Fig. 7 is a fragmentary vertical enlarged sec-- tion through the wall ofthe combustion chamber andshowing the secondary auxiliary air inlet and-5 a control valve therefor.

Fig. 8 is a view similar to Fig. 1 showing a modified form of myinvention and showing an automatic control system therefor.

Figs. 9, 10, 11 and 12 are horizontal sections 10' taken on thecorrespondingly numbered lines of Fig. 8.

Fig. 13 is a detached side elevation of the fluted head through whichthe excessively rich mixture is introduced into the combustion chamber.15

Fig. 14 is a similar view of the sleeve through which the first stage ofauxiliary air is admitted to the combustion chamber. 1

Fig. 15 is a sectional view, partly in elevation, similar to Figs. 1 and8 and showing a further 20 modified form of my invention.

Fig. 16 is a horizontal section taken on line iii-l6, Fig. 15.

The form of the invention shown in Figs. 1-7 comprises a casing formedto provide an enlarged 25 insulated combustion chamber which exhaustsinto a secondary uninsulated radiating chamber preferably of equal size,both being surrounded by a water'jacket, the fuel and air being admittedat the bottom of the combustion chamber and the 30 products ofcombustion being withdrawn from the top of the radiating chamber throughtubes which connect with a manifold which in turn is exhausted by meansof an electric blower or fan. The combustion chamber and radiatingchamber are formed of three casing members comprising a lowerbowl-shaped casing member 20, an intermediate casing member 2| and anupper -casing member 22. The intermediate casing member comprises acentral part 23 of cylindrical form from the lower end of which anannular flange 24 projects outwardly and from the upper end of which anannular flange 25 projects outwardly. An annular manifold 26 is formedon the ,upper side of the lower annular flange 24 and through the uppercasing section 22 and down through the tubes 21 into the manifold 26.

The lower casing section 20 is generally of bowlshaped form and isprovided with anannular outwardly projecting flange 3| at its upper endthrough which cap screws 32 extend which secure the lower casing sectionto the intermediate casing section. The lower casing section is waterjacketed, as indicated at 33, and is also formed to provide a primaryair chamber 34 having an inlet 35; a secondary air chamber 36 having anair inlet 31 under control of a butterfly valve 38 and a third air inletchamber 39 having an inlet 40 under control of a butterfly valve 4|.

A cylindrical shell 45 having upper and lower flanges 46 and 41surrounds and jackets the combustion chamber, the lower flange 41 beingsecured to the lower flange 24 of the intermediate section 2| in anysuitable manner for this purpose. To the upper flange 45 of the shell 45is suitably secured a dome 48 .which is formed to provide a steam orwater outlet 49 for the steam or hot water in the space 50 between theouter shell and the combustion chamber casing. The dome 48 preferablycarries a safety valve 5|, a pressure gage 52 and is formed to provide aboss 53 which carries the upper fitting 54 of a level age glass 55, thelower fitting 56 of this gage 122m carried by a boss 51 in thecylindrical shell The structure described can be supported in anysuitable manner, but is shown as carried by a cylindrical base section60 to which the lower flange 24 of the intermediate casing section 2| issecured, this base section 60 being supported by feet or in any othersuitable manner and'preferably being provided with doors (not shown)through which access can be had to the peepholes, carburetor and theautomatic control equipment which are housed within the base section.

In order to obtain access to each of the tubes 21 for the purpose ofcleaning the same the lower flange 24 of the intermediate section isprovided with a plurality of holes 65 each being in line with acorresponding tube 21 and closed by a plug 66 so that upon removal ofthe plugs the tubes can be cleaned. In addition this lower flange 24 isprovided with four large openings 61, three of these being plugged withlarge plugs 68 and the fourth having an exhaust pipe 69 secured therein.This exhaust pipe 69 is shown as being in the form of an elbow, thelower end of which projects outwardly through the base 60 and connectswith the inlet 18 of a suction fan H which is driven by an electricmotor 12.

An important feature of the present invention consists in liningthecombustion chamber with a refractory insulating material which preventsthe dissipation of heat and insures the maintenance of high temperatureswithin the combustion chamber, this being essential to the eflicientoperation of the combustion apparatus. For this purpose the lower casingsection 20 is provided with a cup-shaped liner I3 of a refractorymaterial, a space I4 being provided between this material and the lowercasing section. In addition, a ring of refractory cement 15 is providedon a shoulder 3|] at the upper end or rim of the bowl shaped lowersection 20 and on this cement is supported a sleeve Hi of refractorymaterial, this sleeve being likewise spaced from the adjacentcylindrical wall 29, as illustrated at I1. On the sleeve 11 is supportedadisk 18 of refractory material, this disk being preferably ofsubstantial thickness and having its rim fitting against the cylindricalwall 23. This disk is preferably held down by a plurality of pins 19which extend through the cylindrical wall 23 and are welded in place.Adjacent its rim the disk 18 is provided with a plurality of slots orholes which permit the products of combustion to escape from thecompletely insulated combustion chamber Bl into the uninsulatedradiating chamber 82. These slots 80 are radially disposed and arepreferably equal in number to and somewhat larger than the tubes 21 soas to provide greater free area through the plate 18 than through thetubes 21.

These slots also are not vertical but are arranged at an angle of 30 andare helically disposed with reference to the axis of the-combustionchamber so that the hot gases passing therethrough are deflected totraverse a helical path and on entering the radiating chamber 82 are notonly thrown outwardly by the centrifugal force against the uninsulatedcylindrical side of the radiating chamber but also traverse these wallsat high velocity so as to increase the heat transfer through thesewalls. The disk 18 is also preferably provided with a very small centralhole 83 so as to avoid any possibility of the formation of dead gaspockets on either the upper or lower sides of the disk.

While any form of fuel can be used the generator is shown as beingadapted for fuel oil which is supplied from a fuel supply pipe 85 to acarburetor 86. The air to this carburetor is preferably preheated,beingwithdrawn through a pipe 84 from the preheating chamber 34. Thecarburetor is of a standard construction used for automotive work, whichis illustrated in section in Fig. 8, having the usual float valve 81 forcontrolling the flow of fuel to main and auxiliary jets 89 and 89, theoutlet ends of which are located in a venturi 90 and a butterflythrottle valve 9! operated by a lever 92 being arranged in the outletneck 93 of the carburetor. Similarly. a butterfly choke valve 94 forcontrolling the richness of the mixture is arranged-in the inlet neck 95of the carburetor and operated by a lever 96, and is set to deliver anexcessively rich mixture of fuel and air so that a back fire will notignite the fuel mixture in the inlet passage wherein sustainedcombustion would not only burn out the inlet parts but also render thecombustion apparatus entirely ineflicient. The outlet neck 93 of thecarburetor is connected by a pipe section 91 with the lower end of thelower combustion chamber casing section 20. An opening 98 is provided inthe lower casing section 20 from the outlet pipe 91 of the carburetor tothe combustion chamber Hi. In the lower end of this opening 98 a sleeve99 is provided" and on this sleeve is supported a second sleeve Hillwhich separates the passage I0l for the fuel mixture from the annularchamber 38 for the first stage of auxiliary air. The sleeve I 90 is proevided with a lower peripheral flange whichrests on the sleeve 99 and isalso provided with an upper peripheral flange I02 which is fitted intothe opening 98. This upper flange I02 is provided with a large number ofslots I93 which are helically disposed with reference to the sleeve soas to set up a whirling motion in the' first stage of auxiliary airwhich is admitted from the air inlet 31 and annular chamber 35 throughthe slots into the combustion chamber. Within the sleeves 99 and Hill isarranged an inverted cylindrical cupshaped member I04 which is open atits lower end and at its upper end is provided with a large number ofhelical slots I05 which extend from approximately midway of its heightthrough its upair inlet sleeve I00 and the fuel inlet head I04 is flushwith the bottom of the bowl-shaped casing section 20 and in a pocketformed in the refractory. If, in starting, an excess of fuel collects inthe combustion chamber, this will flow back into this pocket and berevaporized by the auxiliary air.

Means are provided for preventing a back fire through the carburetor andfor this pupose a check valve is disposed within the inverted cupshapedhead I04 which closes when a condition of back pressure exists. For thispurpose a sleeve I06 is arranged inside. of the cup-shaped head I04 andthe upper end of this sleeve is providedwith an internal bevel I0! whichforms a seat for a valve I08, this valve I08 being of inverted cupshapedform and seating with its rim against the generator and after it is oncestarted ignition of the incoming fuel and air mixture is continuous.This spark plug III is arranged in a pocket II2 which opens through anopening in the refractory lining I3 into the combustion chamber. In theabsence'of provision to prevent it carbon is liable to. form within thispocket and to avoid this condition a 'small groove H3 is provided in thebottom of the pocket II2 and this groove opens to the atmosphere so thatat all times a small stream of air flows through this groove into thecombustion chamber. This air not only cools the spark plug but alsokeeps the pocket II2 free from all carbon deposit.

As the burning gas travels upwardly a second stage of auxiliary airisadmitted through a plurality of nozzles I20 which are set at an angle sothat the auxiliary air from each nozzle issues the admission of air towhichis controlled by the butterfly valve H.

In order to observe the operating conditions within the combustionchamber'peepholes' I22 and I23 are provided through the wall of thelower casing section 20. These peepholes may be made in anysuitablemanner and each is glazed with a disk' of glass. Ohe

other'is directed at the upper corner of the combustion chamberso asto-observe the condition of the burning. gas escaping through theslots.

. tion chamber. 1

of these peepholes is directed at the spark plug III and the-- so. Theseopenings are useful in. seemin the best operating conditions and themaximum economy in fuel consumption. that fuel oil is apt to collect inthe lower peephole I23 in starting and that while the operatingtemperatures in the combustion chamber are high, the temperature in thepeephole I23 is not high enough to vaporize this oil. This trapped fuelis therefore preferably discharged by cutting a slot orgroove I24 in theglass disk of the peephole I23 so that a small stream of air is drawninto the peephole pocket and the fuel redelivered to the combustionchamber.

The water from which the steam is generated is introduced through awater supply pipe I25 under control of a diaphragm valve I25 which inturn is operated by a thermostat I2'I in the exhaust pipe. This waterinlet pipe feeds into the -water jacket 33 around the lower combustionchamber section '20 and from this jacket the water passes upwardlythrough a plurality of passages I28 into the space 50 between thecombustion chamber assembly and the outer shell and the dome 48. Thesepassages- I20 are provided by registering holes in the lower flange 24of the intermediate casing section 2I and in the upper part of the lowercasing section 20, as

It has been found best illustrated in Fig. 6. The combustion apparatuscan be set to deliver any kind of steam desired or to deliver hot waterby adjustment of the thermostat I21. Thus, if saturated steam is desiredthe water level inthe space is maintained as illustrated. If hot wateris to be delivered the entire system. including the outlet pipe 49 andradiators are, of course, flooded. If superheated steam is desired avery low level is maintained in the space 50 so that a part of theheating surface comprising the cylindrical wall 23, the head 28 and apart of the tubes 21 are in contact. with the steam and consequentlysuperheat the steam. Further, the combustion appa- Q I3I of insulatingmaterial. is provided around the .tubular shell 45 and held in place bymetal bands I32. Similarly, the dome 48 is provided withexternalinsulation, as indicated at a I33.

Inthe event that there is a failure in the water supply a safety deviceis provided for shutting down the generator and. preventing burning outof the combustion chamber and tubes. For this purpose a secondthermostat I35'is arranged'in the exhaust pipe and controls a switch I30in one of the-power lines I31 to the blower motor I2.

When the heat in. the exhaust pipe rises to a danger point thethermostat I35 opens the switch I36 and deenergizes the motor I2. whenthis happens the combustion apparatus automatically closes down becauseits operation is conditioned on the maintenance of a sub-atmosphericpressure within the combustion chamber since' otherwise no fuel or airwould be drawn into the .combus Inorde'r to prevent entrained waterm theexhaust gases from throwing the suction fan II out of balance and alsoto prevent this waterfrom entering the stack (not shown) if the ex- V asshown is readily adapted for automatic control. Such an automaticcontrol is ilulstrated in Figs. 8-14. In the form of the invention shownin these figures the combustion chamber is made up of a lowerbowl-shaped casing section I40, 8. second bowl-shaped casing section Iwhich rests on and is secured to the upper part of the lower casingsection I40, a tubular sleeve I42 which is welded to the bowl-shapedsection "I, as indicated at I43, and anupper section I44 which is boltedto the upper end of the cylindrical section I42 and from the center ofwhich the exhaust pipe I45 extends. This exhaust pipe,

connects with a helical coil I 45 which leads downwardly to a fittingI41, this fitting being screwed to the end of a pipe section I48 whichconnects with the inlet of a blower I49. The outlet I50 from the blowerI49 is valved, as indicated at To the rim of the bowl-shaped casingsection I is bolted a ring I52 which is welded to a cylindrical shellI53. To the upper end of this shell I53 is welded a dome I54 carrying asteam outlet connection I55. Water is introduced into the space I56between the combustion chamber casing assembly and the outer shellthrough a water inlet I51 and the entire shell is insulated, asindicated at I58, and preferably also covered with sheet metal I59. Inorder to provide a pressure-tight joint between te exhaust pipe I 48 andthe boiler shell a stufling box I50 is welded to the shell and the pipetightly sealed by the packing in the stufling box. The lower section I40of the combustion chamber casing is lined with a refractory material, asindicated at: I65 and the tubular shell I42is similarly lined, asindicated at I65, and supports a circular plate I61 of refractorymaterial having radial slots I63 which are helically disposed in thesame manner as the slots 80 of the preferred construction and alsohaving a small central opening I69 to prevent pocketing of the gas.

At the lowermost end of the lower casing section I40 an opening I isprovided and in this opening is arranged a sleeve Ill having a loweroutwardly extending flange I12 and an upper outwardly extending flangeI13. Around this sleeve the lower casing section is formed to provide anannular air inlet passage I14 which communicates through ports I with anauxiliary air inlet chamber .I15 provided in one side of a jacket I11around the lower casing section. This air inlet chamber I16 is dividedfrom the primary air inlet preheating chamber I18 by partitions I19 andair is supplied to the auxilia y air chamber through an inlet I80 undercontrol of a. butterfly valve I8I which is operated by a lever I82. Theupper flange I13 of the sleeve "I is provided with a plurality ofhelical slots I84, as best illustrated in Fig. 14, so that the airissuing from the annular chamber I14 through the slots I84 is deflectedto traverse a helical path and to set up a whirling motion of the gasesin the combustion chamber. Within the sleeve III is arranged a secondsleeve I85 which projects downwardly from the lower end of thecombustion chamber casing section I40 and is also formed to provide aninternal seat I86 on which a ball provided with a plurality of helicalgrooves Ill which extend entirely through the skirt so that the fuel isfree to escape-from the inside of the burner head to the combustionchamber and in doing so is deflected to traverse a helical path so as toset up a whirling motion of the burning gases in the combustion chamber.To prevent the ball from sticking in its up position a small hole I90 isprovided through the center of the head, this hole also serving totransmit back fire pressure directly to the top of the ball I12 so thatit closes instantaneously and avoids any danger of combustion continuingin the fuel inlet conduit instead of the combustion chamber althoughthis condition is also avoided by feeding an excessively rich mixture tothe combustion chamber and supplying the necessary additional airindependently.

The carburetor 86 is of the same type as illustrated in the preferredform of the invention and its air inlet pipe 84 communicates with thechamber I18 on the opposite side of the partitions I19 from the chamberI15. Air is admitted to this chamber I18 through a pair of slots I83, asbest illustrated in Figs. 11 and 15. The excessively rich mixture issuesfrom the slots I! and joins the auxiliary air issuing from the slots I84so as to provide a combustible mixture. This mixture is ignited, instarting the combustion apparatus, by a spark plug I96, the pocket I91for which is also preferably kept free from carbon deposits by a smallvent I98 as in the preferred construction. After the burning gases passthe spark plug a second stage of auxiliary air is provided and for thispurpose a plurality of slots I95 are provided in the upper face of thelower combustion chamber section I40 and lead from the combustionchamber into an annular passage 200 which is supplied with preheated airthrough a plurality of ports I which communicafe with the preheatingchamber I16. These slots I99 are disposed so as to sustain the upwardhelical whirling motion of the burning gases.

As in the preferred construction a peephole 202 containing a blockofglass 203 is provided for observing the conditions within the combustionchamber and the glass is provided with a groove 204 to admit a smallstream of air and prevent the formation of a pool of fuel in thispeephole. A water separator 205 is also placed ahead of the pump I49, asin the preferred construction.

In the form of the invention shown in Figs. 8-14 :1 completely automaticcontrol is provided so that the generator will automatically regulateitself and all that is needed in the way of attention is the opening andclosing of a start and stop switch. As illustrated in Fig. 8 thenumerals 2I0 and 2H represent two power lines in one of which a startand stop switch 2I2 is arranged. The motor 2I3 for the blower I49 isarranged across these power lines through wires 2I4 and 2I5rand the wire2I5 connects with the primary winding 2I6 of an ignition transformer2I1, the other winding 2I8 being grounded at one end and connecting withthe spark plug I96 at its other end. The primary winding 2I6 is alsoconnected by a wire 2I9 with the movable contact 228 of a delay relay22I. The stationary contact 223 of the delay relay is connected to theother power line 2 by a wire 224. The delay relay 22I is connecteddirectly across the main power lines 2I0 and 2H and its armature 225which carries the movable contact 220 is pivoted for vertical; movement,as indicated at 226. A rod 221 at the outer end of the armature 225 andthe upper end of this rod connects with 2,173,115 I the arm, of thechoke valve of the car a predetermined setting these valves will be'buretor. gradually closed to maintain the desired oper- In operationwhen it is desired to start the Ming eonditions'of the e e ator- Whenthe combustion apparatus the operator closes the genera-i901 cools downp y. e arm 5 switch 2I2 which establishes a circuit through of the motor23I' strikes a button 248 at the 5 the blower motor 2| 3 so that theblower I49 ex- Outer end of a rod which connects w th the hausts thecombustion chamber and draws the arm 96 the carburetor choke valves fuelmixture into the. combustion chamber, the Valve is normally held p by ap 50- It arr for thi purpose being dr through t a is therefore apparentthat when the generator inlets I83, preheating chamber I18, carburetoris cold the choke valve is closed and in condi- 10 air inlet pipe 84,choke valve 94 which in this tihn for prompt ing. As soon, however, as

'conditionis closed t it maximum extent, venthe generator .warms up thearm 245 releases the turi 90 .in which fuel i ad itt d, and t button 248and permits the choke valveto open. the sleeve I85 and slots Isl intothe combustion In the form of e nv nti n s wn in schamber. At the sametime auxiliary air is adn 16 the ea of the exhaust ases which 15 mjtedth t slots 4. and 99 so as t is not absorbed in the main boiler isutilized for provide a combustible mixture. Coincident with heating w erfo do tic 1188- .FOI' this P the starting of the blower .motor theprimary p the e ust P pe which corresponds winding 2I6 of thetransformer 2" is energized; the p pe I48 in the form of the inventiocurrentpassing from the line 2I0, primary ind, shown in Figs. 8 through14, is provided with a 20 ing 2I6, wire 2I9, closed contact 220 a d :23valve 25I which connects-through'a T 252 with and through wire 224 tothe other power line 2 I I. the coils 253 in a'hOi; w e -tank 254. Wateris This establishes a circuit through th k plug admitted to this tankthrough an inlet pipe 255 and the combustible mixture. drawn into thecomand Withdrawn ro h n Outlet P p 255 d bustion chamber is ignited andth t ithe other end of the coil extends through the 25 placed inoperation. Coincident with the starts e o e ta k 5 nd co w n ejector ingof the blower motor and the establishment illustrated generally at Thisejector inof ignition through the spark plug the relay 22I eludes aVeniillri 258 and a nozzle 259 to w ch is energized and after apredetermined period eam 1 a is pp ed from 8; P p The its armature isdrawn upwardly thereby break nozzle and venturi'serves to draw theproducts mg engagementbetween the conta t 220 d ofcombustion from thecombustion chamber and 223 and breaking the circuit through the primaryhr u h he il 46 an 233 n to ma n n winding 2I6 of the transformer 2" soas to cut the necessary. sub-atm p r Pressures w th n out the flow ofcurrent through the spark plug the combustion ambe ISG. At the same timethe raising of the armah the exhaust is drawn through both the ture 225of the delay relay 22I, through the rod coils and it is ceded o a ve yow tem- 221, gradually opens the choke valve cc of the perature, w i t.t an th p at d air carburetor, choking of the carburetor being onlydrawn into the combustion chamber and'conse' necessary when starting,quently condensation of water in the exhaust As the combustion apparatuscontinues to optakes place and the water must be elimina ed. 40 eratepressure is built up in the steam chamber Where Steam air j i usedexhausting; I56 and this pressure is transmitted through a a W reparator I49 is located in the exhaust pipe 230 to a pressure motor 23Iwhich operates. P p a ter the jet an ii fall. were used it would an rm232 pivoted at 233. The free end of this .c: be located ahead of the fanas inthe other forms'* arm operates a rod 234 which connects with the ofthe invention; J arm 92 of the carburetor throttle and the arm Where thegenerator is used for do estic heat- I32 controlling the admission ofauxiliary air to in it is unnecessary to e t house during the thechamber I16. when the pressure in the summertime and at the same'timeitis desirable steam chamber I 55 reaches a predetermined have a601110115 supply of hot water for dovalue the pressure motor 23Ioperates the rod mestic use. For summer operation a T 25 I is 50 234 togradually close the throttle valve 9| and substituted for the outletelbow I45 at the top auxiliary air valve Ill so as to maintain and ofthe combustion chamber and this T in addigovern the pressureintheboiler. tion to connecting with the coil I46 also con- In the formof the invention shown in Figs. 15 nects with a' pipe 262 which extendsdirectly out and 16 the combustion apparatus is substantially through astufllng box 263 and connects with a the same as that; shown in Figs. 8through. 14 valve 264 and a pipe 265 leading to the -T 252. andtherefore common reference numerals have W h heating 9 the house isdesired the been applied to both. In Figs. 15 and 16 the valve 25I,isclosed and the valve 264 is opened combustion apparatus is mounted upona base or and therefore the exhaust gases instead of exv standardwhich-comprises a pluralityof legs 240 hausting through the coil I44 andheating the to which door sections 2 are pivoted to. open water in themain boiler I56 to a high temperaand close, as indicated at 242, andheld closed by hire P tly to'the' coil 233 so as to heat suitabl'e'snaplatches 243. In this form of the the water in the tank 254 for domesticpurposes. invention the ignition is intendedtooperate conwill bunderstood that e heat e fly tinuously and the automatic control isthermo-t absorbed by the water in the main boiler. I56 5 static insteadof, a pressure control, as illustrated can be utilized by connectingthis boiler with the in figs. 8 through 14; For this purpose the inlet255 to thetank 254. i damper motor 23I', which corresponds to the WhileIhave shown several modifications ofpressure motor 23I in the form shownin Figs. 8 my invention it will be appreciated that the inthrough 14 isactuated by a thermostat 244 and vention is. capable of wide variation.in practice this motor operates an am 245 which is pivand ,theinvention is not to be construedv as oted at 246 and the free endoperates .a rod 241 specifically limited to the constructions shownwhich controls the main throttle valve of the and described but is to beaccorded the full range arburetor and the auxiliaryvairinlet valve so ofequivalents comprehended by the accqmpany,

that when the in the boiler to ins claims. 15

combustion from said combustion chamber and a check valve in said fuelinlet opening.

2. Combustion apparatus, comprising means forming a combustion chamberprovided with a fuel inlet opening in said combustion chamber and meansin said fuel inlet opening for directing the issuing stream of fuel intoa helical path on entering said combustion chamber, means for admittingair to said combustion chamber for admixture with said fuel andincluding means for directing the issuing stream into a helical path onentering said combustion chamber, means for igniting the fuel in saidcombustion chamber, and means at the opposite end of said combustionchamber from said fuel inlet opening for exhausting the products ofcombustion therefrom, said exhausting means creating a sustaineds'ubatmospheric pressure in said combustion chamber.

3. Combustion apparatus; comprising means forming a combustion chamberprovided with a fuel inlet opening, a carburetting device having itsoutlet connected to said fuel inlet opening, means for admitting fueland aid to said carburetting device for mixture therein, means fordrawing the air and fuel through said carburetting device and fuel inletopening into said combustion chamber, a member in said fuel inlet andhaving a helical groove for directing the issuing stream of fuellaterally and to create a turbulence therein, means for igniting themixture in the combustion chamber and means for exhausting the productsof combustion therefrom.

4. Combustion apparatus ofthe character described, comprising meansforming a combustion chamber provided with a fuel inlet openin means insaid fuel inlet opening for directing the issuing stream of fuel into ahelical path on entering said combustion chamber, said combustionchamber being provided with an air inlet for admitting a stream of airinto said fuel stream from the outside thereof, means in said air inletfor directing the air entering said combustion chamber into a helicalpath and whirling in the same direction as said fuel stream, means forigniting the fuel and air in said combustion chamber and means at theopposite end of said combustion chamber from said fuel inlet opena ingfor exhausting the products of combustion.

5. Combustion apparatus of the character described, comprising meansforming a combus-' tion as said fuel stream, means for igniting the fueland air in said combustion chamber, said combustion chamber beingprovided with a sec ond annular air; inlet coaxial with said fuel inletto supply auxiliary air to the stream of burning fuel, means in saidsecond air inlet to deflect the issuing air into a helical path and towhirl in the .same direction as said fuel stream, an exhaust .outlet atthe opposite end of said combustion chamber from said fuel inlet andmeans for drawing the fuel and air into said combustion chamber andexhausting the products of combustion therefrom.

6. Combustion apparatus of the character described, comprising meansforming a combustion chamber having a smooth bowl shaped bottom thesides of which drain into a fuel and air inlet opening provided in thebottom of said combustion chamber, a carburetting device arranged belowsaid combustion chamber and having its out let connected to said inletopening, means for preheating a. supply of primary air, means forcontinuously delivering said preheated air and an excess of fuel to saidcarburetting device whereby a continuous excessively rich andincombustible fuel mixture is delivered through said inlet opening athigh temperature to said combustion chamber, means for continuouslyadmitting secondary air to said combustion chamber for admixture withthe excessively rich fuel mixture therein to dilute said excessivelyrich mixture, means for igniting said diluted mixture,

means for admitting additional air to said combustion chamber foradmixture with said ignited mixture and means for exhausting theproducts of combustion therefrom. I

7. Combustion apparatus of the character described, comprising meansforming a combustion chamber provided in its bottom with a fuel mixtureinlet opening, means for continuously supplying fuel through said fuelinlet opening, said combustion chamber belng provided in its bottom withan annular air inlet opening adjacent to and surrounding said fuel inletopening and continuously and independently admitting air for admixturewith said fuel, means for igniting the fuel and air mixture, saidcombustion chamber being provided in its side with a second annular airinlet opening arranged remote from said fuel inlet opening andsubstantially coaxial therewith and continuously and independentlyadmitting air for admixture with the burning fuel and means forexhausting the products of combustion in asustainedstream from saidcombustion chamber.

8. Combustion apparatus of the character described, comprising meansforming a combustion chamber provided in its bottom with an inletopening, a sleeve arranged in said inlet opening and provided with aninternal fuel inlet opening and an external annular auxiliary air inletopening, the upper part of said sleeve being substantially flush withthe bottom of said combustion chamber, means for supplying anexcessively rich and incombustible mixture of fuel and air through saidfuel inlet opening, means for supplying 'auxiliaryair through saidauxiliary air opening for dilution of said excessively rich mixture,means in said combustion chamber for igniting said diluted mixture andmeans for exhausting the productsof combustion from said combustionchamber.

9. Combustion apparatus of the character described, comprising meansforming a sealed combustion chamber, an exhaust pipe sealed thereto forthe gaseous products of combustion and forming a heat exchanger, meansconnected with said exhaust pipe for exhausting said combustion chamberand maintaining a sub-atmospheric pressure therein, means for admittingliquid fuel and atmospheric air to said combustion chamber underatmospheric pressure and means remote from said combustion chamber forcontrolling'the admission of both said fuel and said air, comprising anexternally actuated valve in said ex-' haust pipe, said products beingsubstantially V trolling the admission of both said fuel and said cooledbefore passing said valve.

10.'A combustion apparatus of the character described, comprising meansforming a sealed combustion chamber, an exhaust pipe sealed thereto forthe gaseous products of combustion" and forming a heat exchanger, meansconnected with said sealed exhaust pipefor exhausting said combustionchamber and maintaing a subatmospheric pressure therein, means foradmitting an excessively -rich mixture of liquid fueland at-- mosphericair to said combustion chamber under: atmospheric pressure, means foradmitting secondary air under atmospheric pressure to said combustionchamber to dilute said excessively rich mixture of fuel and air andmeans for conair, comprising an externally actuated valve in saidexhaust pipe, said products being substantially cooled before passingsaid valve.

MARSDEN C. HUTTO.

